Automatic work and feed device



April 23, 1929. cs. T. POLLARD I AUTQMATIC WORK AND FEED DEVICE Filed Sept. 1924 4 s Sheet's Sheet INVENTOR.

April 23, 1929.

Filed Sept. 1924 5 Sheets-Sheet 2 INVENTOR. :fiwgn 17PM April 23, 1929, PQLLARD 1,709,946

AUTOMATIC WORK AND FEED DEVICE I Filed Sept. 5, 1924 s Sheets-Sheet Patented A... 23, 1 929.

UNITED STATES PATENT OFFICE.

G'UBDO N 'I. POLLARD, OF DENVER, COLORADO.

'Au'rom'rm wonx Am) FEED DEVICE.

Application. filed September 5, 1924. Serial No. 756,187.

The invention relates to improvements in automatic work and feed devices and, al though adapted to many applications, it is more particularly adapted to e used in connection with rotary well drilling machinery and equipment.

The principal object of the invention is to provide an efiicient means for controlling the load on a work device, such as, a cutter or drill, whereby the said work device is actuated and fed to its work in such manner as to be subjected to a substantially constant, predetermined load or resistance regardless of.

value and returning same when the resistance reaches a predetermined value.

Still another object is to provide means whereby a differential or reversing eifectcan be obtained in the usual draw works of a rotary well drill outfit and in the hoisting mechamsm usually employed, whereby the tool may be fed or withdrawn under a fine coni trol.

.A still further object is to provide a mech: anism for accomplishing the above results which may be attached to, and used in con- 'nection with, the present type of rotary drilling equipment. Other objects and advantages reside in the detail construction of the invention, which resultin simplicity, efiiciency, and economy, and which will become more apparent from the following description.

In the following detailed description of the invention, reference is had to the accompanying drawings which form a part hereof. Like numerals refer to like parts in all views of the drawings and throughout the descriptionl In the drawings 1 Fig. 1 is a plan view of one form of the improved automatically operating work and feed device, as-applied to a rotary well drilling outfit. In t is view the differential gear sets are shown in section.

Fig. 2 is a detail cross section through the difierential gear sets and is taken on the line 22, Fig.1.

Fig. 1s a similar cross section through, what Wlll be hereinafter termed, the change gears. This view is taken on the line 3--3,- 1g. 1.

Fig.4 is a vertical section taken on the line 44, Fig. 1. In this view the derrick hoisting mechanism is illustrated.

. ,ig. 5 is an end elevation of an alternate form of the invention. This form is similar to the form of Figs. 1 and 4, with the exception that the differential gear sets, 'illustrated in Fig. 2, have been eliminated.

Fig. 6 is a diagrammatic view illustrating iihe principles involved in the apparatus of 1g.. 5.

Let the numeral 10 designate the usual grief stem of the drilling mechanism,

which is squared near its upper extremity, for v engagement in a rotary table 11, and terminates at the bottom of the well in a drill bit 12. The table 11 carries bevel gear teeth which are engaged by a bevel pinion 13,

through themedium of which, the table 11, drill stem 10, and bit 12, are revolved. The

pinion 13 is carried on the extremity of a drive shaft 14, which is operatively connected to a countershaft 15, through the medium of a pair of miter gears 16 and 17. A braking mechanism 18 is carried by the drive shaft 14, by means of which speed of revolution of the drillbit 12 may be controlled.

Owing to the excessive weight of the drill stem 10, in a deep well, it would be impractical to allow the bit 12 to support the entire weight.- To relieve this weight on the bit 12, the drill stem 10 is supported through the medium of a cable 19 which passes-from a hoist drum 20, upward to the crown block frame 21 of the derrick. where it is trained over multiple sheave wheels- 22 and a multiple block 23, secured to the upper extremity of the drill stem 10; thence over a sheave 24', terminatingin a swivel joint 25 carried by a vertically-operable feed screw 26. the oper-, ation of which will be later described.

- The hoist drum 20 is carried on a drurfi shaft 27, upon which it is freeto revolve but 1 by a clutch 28. a

to which it may be locked Two brake bands 29 are prfvided for the drum 20 through which its movement maybe controlled.

Aflixed to one extremity of the shaft 27,, is i a bevel gear 30 which meshes with teeth carried by a nut 31 which is in turn threaded onto the feed screw 26. Affixed to the other extremity of the drum shaft 27 is a disk 32, which carries a series of planet gears 33.

Acting as an extension of the drum shaft, but separate therefrom, is a short shaft 34, which will be hereinafter designated the second differential shaft. Ailixed to the second differential shaft 34 is a sun pinion 35, which meshes with the planet gears 33 of the shaft 27, and a spur gear 36.

Acting as an extension of the counter shaft 15, but separate therefrom, is a short shaft 37, which will be hereinafter designated the first differential shaft. Afiixed to the first differential shaft 37, is a spur gear 38 and a disk 39 which carries a series of planet gears 40 arranged to mesh with a sun gear 41 securedto the extremity of the countershaft 15/ An idler gear 42 is placed between, and in mesh with both, the spur gears 36 and 38. The gears 36, 38, and 42 are removable and interchangeable so that various gear ratios may be obtained between the differential shafts 34 and 37. They are therefore designated the change gears.

Power for driving the entire mechanism is derived from a power shaft 43 which may be connected through the medium of a sprocket 44 with any suitable source of power. For the device as disclosed, however, the power shaft 43 will be considered the source of power.

The power shaft 43 carries a spur gear 45, which meshes with a. ring gear 46, rotatably mounted on the countershaft 15. The ring gear 46 meshes with a relatively larger though similar ring gear 47.. which is rotatably mounted on the second differential shaft 34.

The ring gears 46 and 47 are free to revolve on their respective shafts and each carry interior gear teeth, those of the gear 46 meshing with the series of planet gears 40 and those of the gear 47 meshing with the series of planet gears 33.

In operation, the drill stem 10 is lowered by allowing the drum 20 to rotate free from its shaft, until the bit 12 has bottomed in the well. The brake 29 is now locked to prevent rotation of the drum 20. Power is supplied from the power shaft 43 and travels through the first differential gear set, comprising gears 46, 40 and 41, to the cou'ntershaft 15, thence to the drive shaft 14 and to the drill bit 12. Power will also How through the change gears 38, 42, and 36; the second differential gear set, comprising gears 33, 35,

- and 47, to the drum shaft 27 and will, through the medium of the bevel gear 30, rotate the nut 31 and allow the feed screw to travel and feed the bit 12 to its work, through the me 2 and 3. The sun gear 35 and ring gear 47 rotate in opposite directions at substantially the same speed, thus holding the planet gears stationary in their orbits so that there will be no feeding of the feed screws 26.

the ring gear 47 and allowing the planet gears to follow the ring gear (clockwise in Fig. 2),

and rotate the shaft 27 so as to cause the nut 31 to draw in the feed screw 26 until the load on the bit has been lessened to predetermined degree, when the sun gear will begin. to re-- seas to let out the feed screw 26 and allow the drill to lower in the well. When the resistance has again built up to normal the normal operation will be resumed.

It will be seen from the above that variations in the operating speed are entirely automatic and that these automatic variations immediately and automatically cause the feed mechanism to adjust the feed to suit conditions.

The feed screw 26 may he splined, as shown at 48, to prevent its rotation and dead ends 49 and 50 are provided so that the shaft 27 maybe used to operate the drum 20, for setting casing etc., without operating the feed screw 26.

In the alternate form, shown in Figs. 5 and 6, the differential gears are eliminated and the nut and screw regulation isaflixed to the drum shaft 27 of the usual draw works, the countershaft 15 having the usual connections, by clutch, to the drum shaft 27. This form is not automatic but is designed to be used in tial action therein'without the use of gears.

In this form, the cable connectionsare identical with the form previously described.

The feed screw 26 is arranged so that it may 1 .be moved upward or downward at any s eed by controlling the rotation of drum sha t 27. The drum may be rotated in either direction by the manipulation of the clutch 28 or the brake 29. Thus, the portion of the cable 19 from the feed screw, indicated at 51 Fig. 6, may be given a plus, minus, or zero movement and that portion of the cable from the drum,

indicated at 52 Fig. 6, may also be given a be slowly released to feed the bit 12 to the work. It is difficult in present practise to release the brake carefull enough so as'not to overfeed, since the fee must be ve slow, usually a release of one-half inch per time being suflicient. With the arrangement above described, however, the operator is allowed greater latitude, since the in ull of the screw will be subtracted from is release and should he accidentally over feed or bottom his drill, the screw 26 will immediately act to again raise it.

While I have herein illustrated and de scribed in some detail, forms of my invention, it is understood that the invention is not to be regarded as limited to the precise constructions described, except in so far as such limita'tions are included within the terms of the accompanying claims, in which, it is my intention to claim all novelty inherent in my' invention as broadly as is permissible in view of the nor art.-

Having thus described my invention, what I claim and desire secured by Letters Patent 1.;The combination of a rotatable and a verticall movable drilling member with differentia rotating means and flexible hanging means controlled to feed a drilling member to its work; said hanging means comprising a rope tackle with one end of the rope attached to a threaded rod; a hoisting drum attached p cally movable drilling tool,'flex1ble means to the other end of the rope and a nut arranged to travel on the said rod, and means for varying the rate of travel of the said nut and the unwinding of the said drum in accordance with theresistance encountered while drilling; thereby causing a differential action in the flexible hanging feeding means.

2. In'a' rotary drilling mechanism, a ro-- tatable and vertically mo'vable drill stem;

means for rotating-said drill stem; fiexible means for supporting and vertically adjusting said stem; a threaded rod secured to the extremity of said flexible means; a nut arranged to travel on and move said rod longi tudinally and means for rotating said nut relatively to the speed of rotation of said drill stem and the resistance encountered in said rotation.

3. In a rotary drilling mechanism com- 3 prising a prime mover, a differential gear set arranged to rotate the said drilling mechanism, a differential gear set arranged to operate in conjunction with the said drilling mechanism and so-arranged to feed a flexible hanging feeding means; said feeding means consisting of a threaded rod operated in a nut which is turned by the primemover; and

connected to the said threaded rod is one end of a rope tackle; while the other end of the said rope tackle is attached to a drum which .is also operated by the said prime mover;

the resulting action imparting a pull, or a let out, to the ends of the said rope tackle,

and connected to drilling. stems, thereby feeding the drilling tool'to its work.

4. .In a rotary drilling mechanism, means for rotating and means for feeding the drill to engagement, arranged in conjunctionwith a double difl'erential gear set, with a rope tackle, a hoisting drum, athreaded rod and nut attached to one end of said rope tackle and the other end of the rope wound around the said'drum, and so operated as to produce a differential action in the said feeding means.

5. Means for rotating and feeding the drill in a rotary drilling mechanism comprising a prime mover; a planetary gear set arranged to be driven bysaid prime mover; said set adapted to rotate said drill; a second planetary gear set driven from said first set; cable means for supporting said drill; a threaded rod secured to one extremity of said cable means; a nut operating to move said rod longitudinally; a reel secured to the other extremity of said cable means, saidnut and saidreel being arranged to be operated from said second set of planetary gears. 1

6. The combination of a rotatable, vertifor supporting said tool at some intermediate I point in said flexible means; a longitudinally movable feed screw secured to one extremity cunnon LI. ROLLARD. 

